Why are the P{sub n} and S{sub n} Methods Equivalent (open access)

Why are the P{sub n} and S{sub n} Methods Equivalent

The author assumes that the reader is familiar with the Spherical harmonics, Pn, method and the discrete ordinates, S{sub n}, method; for a derivation of the equations used in these methods. I will only discuss the Boltzmann equation in one dimension, and the Sn method using Gaussian quadrature. I will do this merely to simplify the following discussion; once you understand the concepts presented here you can easily extend the conclusions to more general situations. Why are the spherical harmonics P{sub n} and discrete ordinate S{sub n} methods, or more correctly the P{sub n} and S{sub n+1} methods, equivalent, e.g., P{sub 3} is equivalent to S{sub 4}? When the S{sub n} method uses a Gaussian quadrature most textbooks will tell you that both methods are equivalent to assuming that the angular flux can be represented by a Legendre polynomial expansion of order n. Most textbooks are wrong [1]. We know that the S{sub n} method constrains the ''particles'' to travel in discrete directions; when Gaussian quadrature is used these discrete directions correspond to the zeros of the Legendre polynomial P{sub n+1}({mu}). What is not immediately obvious is that the P{sub n} method constrains the ''particles'' in exactly the same way. …
Date: September 19, 2001
Creator: Cullen, D E
Object Type: Report
System: The UNT Digital Library
A Catalog of Geologic Data for the Hanford Site (open access)

A Catalog of Geologic Data for the Hanford Site

This report catalogs the existing geologic data that can be found in various databases, published and unpublished reports, and in individuals' technical files. The scope of this catalog is primarily on the 100, 200, and 300 Areas, with a particular emphasis on the 200 Areas. Over 2,922 wells are included in the catalog. Nearly all of these wells (2,459) have some form of driller's or geologist's log. Archived samples are available for 1,742 wells. Particle size data are available from 1,078 wells and moisture data are available from 356 wells. Some form of chemical property data is available from 588 wells. However, this catalog is by no means complete. Numerous individuals have been involved in various geologic-related studies of the Hanford Site. The true extent of unpublished data retained in their technical files is unknown. However, this data catalog is believed to represent the majority (>90%) of the geologic data that is currently retrievable.
Date: September 19, 2001
Creator: Horton, Duane G.; Last, George V.; Gilmore, Tyler J. & Bjornstad, Bruce N.
Object Type: Report
System: The UNT Digital Library
A highly portable, rapidly deployable system for eddy covariance measurements of CO2 fluxes (open access)

A highly portable, rapidly deployable system for eddy covariance measurements of CO2 fluxes

To facilitate the study of flux heterogeneity within a region, the authors have designed, built, and field-tested a highly portable, rapidly deployable, eddy covariance CO{sub 2} flux measurement system. The system is built from off-the-shelf parts and was assembled at a minimal cost. The unique combination of features of this system allow for a very rapid deployment with a minimal number of field personnel. The system is capable of making high precision, unattended measurements of turbulent CO{sub 2} fluxes, latent heat (LE) fluxes, sensible heat fluxes (H), and momentum transfer fluxes. In addition, many of the meteorological and ecosystem variables necessary for quality control of the fluxes and for running ecosystem models are measured. A side-by-side field comparison of the system at a pair of established AmeriFlux sites has verified that, for single measurements, the system is capable of CO{sub 2} flux accuracy of about {+-} 1.2 {micro}mole/m{sup 2}/sec, LE flux accuracy of about {+-} 15 Watts/m{sup 2}, H flux accuracy of about {+-} 7 Watts/m{sup 2}, and momentum transfer flux accuracy of about {+-} 11 gm-m/sec/sec. System deployment time is between 2 and 4 hours by a single person. The system was measured to draw between 30 and 35 …
Date: September 19, 2001
Creator: Billesbach, David P.; Fischer, Marc L.; Torn, Margaret S. & Berry, Joe A.
Object Type: Article
System: The UNT Digital Library
Irradiation testing of actinide transmutation fuels in the advanced test reactor. (open access)

Irradiation testing of actinide transmutation fuels in the advanced test reactor.

The first irradiation experiment to evaluate the technical feasibility of proposed acitnide transmutation fuels for the US. Accelerator Transmutation of Waste program is currently under design. The goal of this irradiation experiment is to obtain initial irradiation performance data on candidate transmutation fuel concepts. The candidate fuels include non-fertile variations of (1) metallic alloys, (2) nitrides, (3) oxides, and (4) metal-matrix dispersion fuels. These fuels will be irradiated in the form of rodlets in the Advanced Test Reactor in Idaho beginning in September 2002. it is expected that postirradiation examinations will be performed on these fuels at the {approx} 7 and 20 at.-% burnup levels. This paper presents the design of the irradiation test vehicle and the fuel rodlets; the test matrix of fuel variations, the target test conditions; and the planned postirradiation examinations.
Date: September 19, 2001
Creator: Hayes, S. L.; Meyer, M. K. & Crawford, D. C.
Object Type: Article
System: The UNT Digital Library
Kaon interferometry: A sensitive probe of the QCD equation of state? (open access)

Kaon interferometry: A sensitive probe of the QCD equation of state?

None
Date: September 19, 2001
Creator: Soff, Sven; Bass, Steffen A.; Hardtke, David H. & Panitkin, Sergey Y.
Object Type: Article
System: The UNT Digital Library
High-Order Boundary Condition Perturbation Theory for the Neutron Transport Equation (open access)

High-Order Boundary Condition Perturbation Theory for the Neutron Transport Equation

First-order boundary condition perturbation theory is extended to nth-order in transport theory for eigenvalue problems. In particular, using an unperturbed (known) solution, formalisms are developed to determine the solution to the neutron transport equation when the boundary condition of the system is perturbed. The new method requires the computation of an adjoint Green's function. The numerical solution of this function is discussed. Finally, four numerical examples are provided to verify the validity of the formalisms presented.
Date: September 19, 2001
Creator: McKinley, M. S. & Rahnema, F
Object Type: Report
System: The UNT Digital Library
Ballooning Stability of the Compact Quasiaxially Symmetric Stellarator (open access)

Ballooning Stability of the Compact Quasiaxially Symmetric Stellarator

The magnetohydrodynamic (MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), expected to achieve good stability and particle confinement is examined with a method that can lead to estimates of global stability. Making use of fully 3D, ideal-MHD stability codes, the QAS beta is predicted to be limited above 4% by ballooning and high-n kink modes. Here MHD stability is analyzed through the calculation and examination of the ballooning mode eigenvalue isosurfaces in the 3-space [s, alpha, theta(subscript ''k'')]; s is the edge normalized toroidal flux, alpha is the field line variable, and theta(subscript ''k'') is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, with new types of nonsymmetric, eigenvalue isosurfaces in both the stable and unstable spectrum. The isosurfaces around the most unstable points i n parameter space (well above marginal) are topologically spherical. In such cases, attempts to use ray tracing to construct global ballooning modes lead to a k-space runaway. Introduction of a reflecting cutoff in k(perpendicular) to model numerical truncation or finite Larmor radius (FLR) yields chaotic ray paths ergodically filling the allowed phase space, indicating that …
Date: September 19, 2001
Creator: Redi, M. H.; Canik, J.; Dewar, R. L.; Johnson, J. L.; Klasky, S.; Cooper, W. A. et al.
Object Type: Report
System: The UNT Digital Library
Statistical Correlations and Intensity Spiking in the Sase Fel. (open access)

Statistical Correlations and Intensity Spiking in the Sase Fel.

In the linear regime before saturation, we describe the statistical correlations in the narrow band chaotic output of the SASE FEL. At a fixed position along the undulator axis, we derive joint probability distributions for the intensity in the output pulse to have values I{sub 1} and I{sub 2} at times t{sub 1} and t{sub 2}, and for the spectral intensity to have values {tilde I}{sub 1} and {tilde I}{sub 2} at frequencies {omega}{sub 1} and {omega}{sub 2}. Probability distributions for the peak values of intensity in the time and frequency domains are also determined.
Date: September 19, 2001
Creator: Krinsky, S. & Gluckstern, R. L.
Object Type: Article
System: The UNT Digital Library
Improved MK42 Melting Model (open access)

Improved MK42 Melting Model

An improved Mark 42 melting model has been defined for establishing confinement protection limits (CPLs). This report describes the new melting model and its application in computing CPLs.
Date: September 19, 2001
Creator: Tudor, A. A.
Object Type: Report
System: The UNT Digital Library
Statistical Correlations and Intensity Spiking in the Sase Fel. (open access)

Statistical Correlations and Intensity Spiking in the Sase Fel.

In the linear regime before saturation, we describe the statistical correlations in the narrow band chaotic output of the SASE FEL. At a fixed position along the undulator axis, we derive joint probability distributions for the intensity in the output pulse to have values I{sub 1} and I{sub 2} at times t{sub 1} and t{sub 2}, and for the spectral intensity to have values {tilde I}{sub 1} and {tilde I}{sub 2} at frequencies {omega}{sub 1} and {omega}{sub 2}. Probability distributions for the peak values of intensity in the time and frequency domains are also determined.
Date: September 19, 2001
Creator: Krinsky, S. & Gluckstern, R. L.
Object Type: Article
System: The UNT Digital Library
A Catalog of Geologic Data for the Hanford Site (open access)

A Catalog of Geologic Data for the Hanford Site

This report catalogs the existing geologic data that can be found in various databases, published and unpublished reports, and in individuals' technical files. The scope of this catalog is primarily on the 100, 200, and 300 Areas, with a particular emphasis on the 200 Areas. Over 2,922 wells are included in the catalog. Nearly all of these wells (2,459) have some form of driller's or geologist's log. Archived samples are available for 1,742 wells. Particle size data are available from 1,078 wells and moisture data are available from 356 wells. Some form of chemical property data is available from 588 wells. However, this catalog is by no means complete. Numerous individuals have been involved in various geologic-related studies of the Hanford Site. The true extent of unpublished data retained in their technical files is unknown. However, this data catalog is believed to represent the majority (>90%) of the geologic data that is currently retrievable.
Date: September 19, 2001
Creator: Horton, Duane G; Last, George V; Gilmore, Tyler J & Bjornstad, Bruce N
Object Type: Report
System: The UNT Digital Library
Initial Studies of Core and Edge Transport of NSTX Plasmas (open access)

Initial Studies of Core and Edge Transport of NSTX Plasmas

Rapidly developing diagnostic, operational, and analysis capability is enabling the first detailed local physics studies to begin in high-beta plasmas of the National Spherical Torus Experiment (NSTX). These studies are motivated in part by energy confinement times in neutral-beam-heated discharges that are favorable with respect to predictions from the ITER-89P scaling expression. Analysis of heat fluxes based on profile measurements with neutral-beam injection (NBI) suggest that the ion thermal transport may be exceptionally low, and that electron thermal transport is the dominant loss channel. This analysis motivates studies of possible sources of ion heating not presently accounted for by classical collisional processes. Gyrokinetic microstability studies indicate that long wavelength turbulence with k(subscript ''theta'') rho(subscript ''i'') {approx} 0.1-1 may be suppressed in these plasmas, while modes with k(subscript ''theta'') rho(subscript ''i'') {approx} 50 may be robust. High-harmonic fast-wave (HHFW) heating efficiently heats electrons on NSTX, and studies have begun using it to assess transport in the electron channel. Regarding edge transport, H-mode [high-confinement mode] transitions occur with either NBI or HHFW heating. The power required for low-confinement mode (L-mode) to H-mode transitions far exceeds that expected from empirical edge-localized-mode-free H-mode scaling laws derived from moderate aspect ratio devices. Finally, initial fluctuation …
Date: September 19, 2001
Creator: Synakowski, E. J.; Bell, M. G.; Bell, R. E.; Bush, C. E.; Bourdelle, C.; Darrow, D. et al.
Object Type: Report
System: The UNT Digital Library
Pretest Predictions for Phase II Ventilation Tests (open access)

Pretest Predictions for Phase II Ventilation Tests

The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, and concrete pipe walls that will be developed during the Phase II ventilation tests involving various test conditions. The results will be used as inputs to validating numerical approach for modeling continuous ventilation, and be used to support the repository subsurface design. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the Phase II ventilation tests, and describe numerical methods that are used to calculate the effects of continuous ventilation. The calculation is limited to thermal effect only. This engineering work activity is conducted in accordance with the ''Technical Work Plan for: Subsurface Performance Testing for License Application (LA) for Fiscal Year 2001'' (CRWMS M&O 2000d). This technical work plan (TWP) includes an AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', activity evaluation (CRWMS M&O 2000d, Addendum A) that has determined this activity is subject to the YMP quality assurance (QA) program. The calculation is developed in accordance with the AP-3.12Q procedure, ''Calculations''. Additional background information regarding this activity is contained in the ''Development Plan for Ventilation Pretest Predictive Calculation'' …
Date: September 19, 2001
Creator: Sun, Yiming
Object Type: Report
System: The UNT Digital Library